Method and user equipment for blocking network access by ACDC

ABSTRACT

A disclosure of the present specification provides a network access blocking method performed by a user equipment. The method may comprise the steps of: receiving application specific congestion control for data communication (ACDC) blocking information and access class barring (ACB) blocking information; determining the category of an application being executed according to a network access attempt by the application; performing an ACDC blocking check on the basis of the determined category and the received ACDC blocking information. Here, when the network access attempt by the application is not blocked as a result of the ACDC blocking check, an ACB blocking check on the basis of the ACB blocking information may be skipped.

This application is a continuation of U.S. patent application Ser. No.15/113,802, filed on Jul. 22, 2016, now U.S. Pat. No. 9,860,824, whichis the National Stage filing under 35 U.S.C. 371 of InternationalApplication No. PCT/KR2015/012062, filed on Nov. 10, 2015, which claimsthe benefit of U.S. Provisional Application No. 62/077,324, filed onNov. 10, 2014, 62/106,220, filed on Jan. 22, 2015, 62/157,433, filed onMay 5, 2015, 62/157,987, filed on May 7, 2015, 62/162,839, filed on May18, 2015, and 62/164,575, filed on May 21, 2015, the contents of whichare all hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a technique of barring access forcongestion control in a mobile communication system.

Related Art

In 3GPP in which technical standards for mobile communication systemsare established, in order to handle 4th generation communication andseveral related forums and new technologies, research on Long TermEvolution/System Architecture Evolution (LTE/SAE) technology has startedas part of efforts to optimize and improve the performance of 3GPPtechnologies from the end of the year 2004.

SAE that has been performed based on 3GPP SA WG2 is research regardingnetwork technology that aims to determine the structure of a network andto support mobility between heterogeneous networks in line with an LTEtask of a 3GPP TSG RAN and is one of recent important standardizationissues of 3GPP. SAE is a task for developing a 3GPP system into a systemthat supports various radio access technologies based on an IP, and thetask has been carried out for the purpose of an optimized packet-basedsystem which minimizes transmission delay with a more improved datatransmission capability.

An Evolved Packet System (EPS) higher level reference model defined in3GPP SA WG2 includes a non-roaming case and roaming cases having variousscenarios, and for details therefor, reference can be made to 3GPPstandard documents TS 23.401 and TS 23.402. A network configuration ofFIG. 1 has been briefly reconfigured from the EPS higher level referencemodel.

FIG. 1 shows the configuration of an evolved mobile communicationnetwork.

An Evolved Packet Core (EPC) may include various elements. FIG. 1illustrates a Serving Gateway (S-GW) 52, a Packet Data Network Gateway(PDN GW) 53, a Mobility Management Entity (MME) 51, a Serving GeneralPacket Radio Service (GPRS) Supporting Node (SGSN), and an enhancedPacket Data Gateway (ePDG) that correspond to some of the variouselements.

The S-GW 52 is an element that operates at a boundary point between aRadio Access Network (RAN) and a core network and has a function ofmaintaining a data path between an eNodeB 22 and the PDN GW 53.Furthermore, if a terminal (or User Equipment (UE) moves in a region inwhich service is provided by the eNodeB 22, the S-GW 52 plays a role ofa local mobility anchor point. That is, for mobility within an E-UTRAN(i.e., a Universal Mobile Telecommunications System (Evolved-UMTS)Terrestrial Radio Access Network defined after 3GPP release-8), packetscan be routed through the S-GW 52. Furthermore, the S-GW 52 may play arole of an anchor point for mobility with another 3GPP network (i.e., aRAN defined prior to 3GPP release-8, for example, a UTRAN or GlobalSystem for Mobile communication (GSM) (GERAN)/Enhanced Data rates forGlobal Evolution (EDGE) Radio Access Network).

The PDN GW (or P-GW) 53 corresponds to the termination point of a datainterface toward a packet data network. The PDN GW 53 can support policyenforcement features, packet filtering, charging support, etc.Furthermore, the PDN GW (or P-GW) 53 can play a role of an anchor pointfor mobility management with a 3GPP network and a non-3GPP network(e.g., an unreliable network, such as an Interworking Wireless LocalArea Network (I-WLAN), a Code Division Multiple Access (CDMA) network,or a reliable network, such as WiMax).

In the network configuration of FIG. 1, the S-GW 52 and the PDN GW 53have been illustrated as being separate gateways, but the two gatewaysmay be implemented in accordance with a single gateway configurationoption.

The MME 51 is an element for performing the access of a terminal to anetwork connection and signaling and control functions for supportingthe allocation, tracking, paging, roaming, handover, etc. of networkresources. The MME 51 controls control plane functions related tosubscribers and session management. The MME 51 manages numerous eNodeBs22 and performs conventional signaling for selecting a gateway forhandover to another 2G/3G networks. Furthermore, the MME 51 performsfunctions, such as security procedures, terminal-to-network sessionhandling, and idle terminal location management.

The SGSN handles all packet data, such as a user's mobility managementand authentication for different access 3GPP networks (e.g., a GPRSnetwork and an UTRAN/GERAN).

The ePDG plays a role of a security node for an unreliable non-3GPPnetwork (e.g., an I-WLAN and a Wi-Fi hotspot).

As described with reference to FIG. 1, a terminal (or UE) having an IPcapability can access an IP service network (e.g., IMS), provided by aservice provider (i.e., an operator), via various elements within an EPCbased on non-3GPP access as well as based on 3GPP access.

Furthermore, FIG. 1 shows various reference points (e.g., S1-U andS1-MME). In a 3GPP system, a conceptual link that connects two functionsthat are present in the different function entities of an E-UTRAN and anEPC is called a reference point. Table 1 below defines reference pointsshown in FIG. 1. In addition to the reference points shown in theexample of Table 1, various reference points may be present depending ona network configuration.

TABLE 1 REFERENCE POINT DESCRIPTION S1-MME A reference point for acontrol plane protocol between the E-UTRAN and the MME S1-U A referencepoint between the E-UTRAN and the S-GW for path switching betweeneNodeBs during handover and user plane tunneling per bearer S3 Areference point between the MME and the SGSN that provides the exchangeof pieces of user and bearer information for mobility between 3GPPaccess networks in idle and/or activation state. This reference pointcan be used intra-PLMN or inter-PLMN (e.g. in the case of Inter-PLMNHO). S4 A reference point between the SGW and the SGSN that providesrelated control and mobility support between the 3GPP anchor functionsof a GPRS core and the S-GW. Furthermore, if a direct tunnel is notestablished, the reference point provides user plane tunneling. S5 Areference point that provides user plane tunneling and tunnel managementbetween the S-GW and the PDN GW. The reference point is used for S-GWrelocation due to UE mobility and if the S-GW needs to connect to anon-collocated PDN GW for required PDN connectivity S11 A referencepoint between the MME and the S-GW SGi A reference point between the PDNGW and the PDN. The PDN may be a public or private PDN external to anoperator or may be an intra-operator PDN, e.g., for the providing of IMSservices. This reference point corresponds to Gi for 3GPP access.

Among the reference points shown in FIG. 1, S2a and S2b correspond tonon-3GPP interfaces. S2a is a reference point providing the user planewith related control and mobility support between a PDN GW and areliable non-3GPP access. S2b is a reference point providing the userplane with mobility support and related control between a PDN GW and anePDG.

FIG. 2 is an exemplary diagram showing the architecture of a commonE-UTRAN and a common EPC.

As shown in FIG. 2, the eNodeB 20 can perform functions, such as routingto a gateway while RRC connection is activated, the scheduling andtransmission of a paging message, the scheduling and transmission of abroadcast channel (BCH), the dynamic allocation of resources to UE inuplink and downlink, a configuration and providing for the measurementof the eNodeB 20, control of a radio bearer, radio admission control,and connection mobility control. The EPC can perform functions, such asthe generation of paging, the management of an LTE_IDLE state, theciphering of a user plane, control of an EPS bearer, the ciphering ofNAS signaling, and integrity protection.

FIG. 3 is an exemplary diagram showing the structure of a radiointerface protocol in a control plane between UE and an eNodeB, and FIG.4 is another exemplary diagram showing the structure of a radiointerface protocol in a control plane between UE and an eNodeB.

The radio interface protocol is based on a 3GPP radio access networkstandard. The radio interface protocol includes a physical layer, a datalink layer, and a network layer horizontally, and it is divided into auser plane for the transmission of information and a control plane forthe transfer of a control signal (or signaling).

The protocol layers may be classified into a first layer (L1), a secondlayer (L2), and a third layer (L3) based on three lower layers of theOpen System Interconnection (OSI) reference model that is widely knownin communication systems.

The layers of the radio protocol of the control plane shown in FIG. 3and the radio protocol in the user plane of FIG. 4 are described below.

The physical layer PHY, that is, the first layer, provides informationtransfer service using physical channels. The PHY layer is connected toa Medium Access Control (MAC) layer placed in a higher layer through atransport channel, and data is transferred between the MAC layer and thePHY layer through the transport channel. Furthermore, data istransferred between different PHY layers, that is, PHY layers on thesender side and the receiver side, through the PHY layer.

A physical channel is made up of multiple subframes on a time axis andmultiple subcarriers on a frequency axis. Here, one subframe is made upof a plurality of symbols and a plurality of subcarriers on the timeaxis. One subframe is made up of a plurality of resource blocks, and oneresource block is made up of a plurality of symbols and a plurality ofsubcarriers. A Transmission Time Interval (TTI), that is, a unit timeduring which data is transmitted, is 1 ms corresponding to one subframe.

In accordance with 3GPP LTE, physical channels that are present in thephysical layer of the sender side and the receiver side can be dividedinto a Physical Downlink Shared Channel (PDSCH) and a Physical UplinkShared Channel (PUSCH), that is, data channels, and a Physical DownlinkControl Channel (PDCCH), a Physical Control Format Indicator Channel(PCFICH), a Physical Hybrid-ARQ Indicator Channel (PHICH), and aPhysical Uplink Control Channel (PUCCH), that is, control channels.

A PCFICH that is transmitted in the first OFDM symbol of a subframecarries a Control Format Indicator (CFI) regarding the number of OFDMsymbols (i.e., the size of a control region) used to send controlchannels within the subframe. A wireless device first receives a CFI ona PCFICH and then monitors PDCCHs.

Unlike a PDCCH, a PCFICH is transmitted through the fixed PCFICHresources of a subframe without using blind decoding.

A PHICH carries positive-acknowledgement (ACK)/negative-acknowledgement(NACK) signals for an uplink (UL) Hybrid Automatic Repeat reQuest(HARQ). ACK/NACK signals for UL data on a PUSCH that is transmitted by awireless device are transmitted on a PHICH.

A Physical Broadcast Channel (PBCH) is transmitted in four former OFDMsymbols of the second slot of the first subframe of a radio frame. ThePBCH carries system information that is essential for a wireless deviceto communicate with an eNodeB, and system information transmittedthrough a PBCH is called a Master Information Block (MIB). In contrast,system information transmitted on a PDSCH indicated by a PDCCH is calleda System Information Block (SIB).

A PDCCH can carry the resource allocation and transport format of adownlink-shared channel (DL-SCH), information about the resourceallocation of an uplink shared channel (UL-SCH), paging information fora PCH, system information for a DL-SCH, the resource allocation of anupper layer control message transmitted on a PDSCH, such as a randomaccess response, a set of transmit power control commands for pieces ofUE within a specific UE group, and the activation of a Voice overInternet Protocol (VoIP). A plurality of PDCCHs can be transmittedwithin the control region, and UE can monitor a plurality of PDCCHs. APDCCH is transmitted on one Control Channel Element (CCE) or anaggregation of multiple contiguous CCEs. A CCE is a logical allocationunit used to provide a PDCCH with a coding rate according to the stateof a radio channel A CCE corresponds to a plurality of resource elementgroups. The format of a PDCCH and the number of bits of a possible PDCCHare determined by a relationship between the number of CCEs and a codingrate provided by CCEs.

Control information transmitted through a PDCCH is called DownlinkControl Information (DCI). DCI can include the resource allocation of aPDSCH (also called a downlink (DL) grant)), the resource allocation of aPUSCH (also called an uplink (UL) grant), a set of transmit powercontrol commands for pieces of UE within a specific UE group, and/or theactivation of a Voice over Internet Protocol (VoIP).

Several layers are present in the second layer. First, a Medium AccessControl (MAC) layer functions to map various logical channels to varioustransport channels and also plays a role of logical channel multiplexingfor mapping multiple logical channels to one transport channel. The MAClayer is connected to a Radio Link Control (RLC) layer, that is, ahigher layer, through a logical channel. The logical channel isbasically divided into a control channel through which information ofthe control plane is transmitted and a traffic channel through whichinformation of the user plane is transmitted depending on the type oftransmitted information.

The RLC layer of the second layer functions to control a data size thatis suitable for sending, by a lower layer, data received from a higherlayer in a radio section by segmenting and concatenating the data.Furthermore, in order to guarantee various types of QoS required byradio bearers, the RLC layer provides three types of operation modes: aTransparent Mode (TM), an Un-acknowledged Mode (UM), and an AcknowledgedMode (AM). In particular, AM RLC performs a retransmission functionthrough an Automatic Repeat and Request (ARQ) function for reliable datatransmission.

The Packet Data Convergence Protocol (PDCP) layer of the second layerperforms a header compression function for reducing the size of an IPpacket header containing control information that is relatively large insize and unnecessary in order to efficiently send an IP packet, such asIPv4 or IPv6, in a radio section having a small bandwidth when sendingthe IP packet. Accordingly, transmission efficiency of the radio sectioncan be increased because only essential information is transmitted inthe header part of data. Furthermore, in an LTE system, the PDCP layeralso performs a security function. The security function includesciphering for preventing the interception of data by a third party andintegrity protection for preventing the manipulation of data by a thirdparty.

A Radio Resource Control (RRC) layer at the highest place of the thirdlayer is defined only in the control plane and is responsible forcontrol of logical channels, transport channels, and physical channelsin relation to the configuration, re-configuration, and release of RadioBearers (RBs). Here, the RB means service provided by the second layerin order to transfer data between UE and an E-UTRAN.

If an RRC connection is present between the RRC layer of UE and the RRClayer of a wireless network, the UE is in an RRC_CONNECTED state. Ifnot, the UE is in an RRC_IDLE state.

An RRC state and an RRC connection method of UE are described below. TheRRC state means whether or not the RRC layer of UE has been logicallyconnected to the RRC layer of an E-UTRAN. If the RRC layer of UE islogically connected to the RRC layer of an E-UTRAN, it is called theRRC_CONNECTED state. If the RRC layer of UE is not logically connectedto the RRC layer of an E-UTRAN, it is called the RRC_IDLE state. SinceUE in the RRC_CONNECTED state has an RRC connection, an E-UTRAN cancheck the existence of the UE in a cell unit, and thus control the UEeffectively. In contrast, if UE is in the RRC_IDLE state, an E-UTRANcannot check the existence of the UE, and a core network is managed in aTracking Area (TA) unit, that is, an area unit greater than a cell. Thatis, only the existence of UE in the RRC_IDLE state is checked in an areaunit greater than a cell. In such a case, the UE needs to shift to theRRC_CONNECTED state in order to be provided with common mobilecommunication service, such as voice or data. Each TA is classifiedthrough Tracking Area Identity (TAI). UE can configure TAI throughTracking Area Code (TAC), that is, information broadcasted by a cell.

When a user first turns on the power of UE, the UE first searches for aproper cell, establishes an RRC connection in the corresponding cell,and registers information about the UE with a core network. Thereafter,the UE stays in the RRC_IDLE state. The UE in the RRC_IDLE state(re)selects a cell if necessary and checks system information or paginginformation. This process is called camp on. When the UE in the RRC_IDLEstate needs to establish an RRC connection, the UE establishes an RRCconnection with the RRC layer of an E-UTRAN through an RRC connectionprocedure and shifts to the RRC_CONNECTED state. A case where the UE inthe RRC_IDLE state needs to establish with an RRC connection includesmultiple cases. The multiple cases may include, for example, a casewhere UL data needs to be transmitted for a reason, such as a callattempt made by a user and a case where a response message needs to betransmitted in response to a paging message received from an E-UTRAN.

A Non-Access Stratum (NAS) layer placed over the RRC layer performsfunctions, such as session management and mobility management.

The NAS layer shown in FIG. 3 is described in detail below.

Evolved Session Management (ESM) belonging to the NAS layer performsfunctions, such as the management of default bearers and the managementof dedicated bearers, and ESM is responsible for control that isnecessary for UE to use PS service from a network. Default bearerresources are characterized in that they are allocated by a network whenUE first accesses a specific Packet Data Network (PDN) or accesses anetwork. Here, the network allocates an IP address available for UE sothat the UE can use data service and the QoS of a default bearer. LTEsupports two types of bearers: a bearer having Guaranteed Bit Rate (GBR)QoS characteristic that guarantees a specific bandwidth for thetransmission and reception of data and a non-GBR bearer having the besteffort QoS characteristic without guaranteeing a bandwidth. A defaultbearer is assigned a non-GBR bearer, and a dedicated bearer may beassigned a bearer having a GBR or non-GBR QoS characteristic.

In a network, a bearer assigned to UE is called an Evolved PacketService (EPS) bearer. When assigning an EPS bearer, a network assignsone ID. This is called an EPS bearer ID. One EPS bearer has QoScharacteristics of a Maximum Bit Rate (MBR) and a Guaranteed Bit Rate(GBR) or an Aggregated Maximum Bit Rate (AMBR).

Meanwhile, in FIG. 3, the RRC layer, the RLC layer, the MAC layer, andthe PHY layer placed under the NAS layer are also collectively called anAccess Stratum (AS).

FIG. 5a is a flowchart illustrating a random access process in 3GPP LTE.

The random access process is used for UE 10 to obtain UL synchronizationwith a base station, that is, an eNodeB 20, or to be assigned UL radioresources.

The UE 10 receives a root index and a physical random access channel(PRACH) configuration index from the eNodeB 20. 64 candidate randomaccess preambles defined by a Zadoff-Chu (ZC) sequence are present ineach cell. The root index is a logical index that is used for the UE togenerate the 64 candidate random access preambles.

The transmission of a random access preamble is limited to specific timeand frequency resources in each cell. The PRACH configuration indexindicates a specific subframe on which a random access preamble can betransmitted and a preamble format.

The UE 10 sends a randomly selected random access preamble to the eNodeB20. Here, the UE 10 selects one of the 64 candidate random accesspreambles. Furthermore, the UE selects a subframe corresponding to thePRACH configuration index. The UE 10 sends the selected random accesspreamble in the selected subframe.

The eNodeB 20 that has received the random access preamble sends aRandom Access Response (RAR) to the UE 10. The random access response isdetected in two steps. First, the UE 10 detects a PDCCH masked with arandom access-RNTI (RA-RNTI). The UE 10 receives a random accessresponse within a Medium Access Control (MAC) Protocol Data Unit (PDU)on a PDSCH that is indicated by the detected PDCCH.

FIG. 5b illustrates a connection process in a radio resource control(RRC) layer.

FIG. 5b shows an RRC state depending on whether there is an RRCconnection. The RRC state denotes whether the entity of the RRC layer ofUE 10 is in logical connection with the entity of the RRC layer ofeNodeB 20, and if yes, it is referred to as RRC connected state, and ifno as RRC idle state.

In the connected state, UE 10 has an RRC connection, and thus, theE-UTRAN may grasp the presence of the UE on a cell basis and may thuseffectively control UE 10. In contrast, UE 10 in the idle state cannotgrasp eNodeB 20 and is managed by a core network on the basis of atracking area that is larger than a cell. The tracking area is a set ofcells. That is, UE 10 in the idle state is grasped for its presence onlyon a larger area basis, and the UE should switch to the connected stateto receive a typical mobile communication service such as voice or dataservice.

When the user turns on UE 10, UE 10 searches for a proper cell and staysin idle state in the cell. UE 10, when required, establishes an RRCconnection with the RRC layer of eNodeB 20 through an RRC connectionprocedure and transits to the RRC connected state.

There are a number of situations where the UE staying in the idle stateneeds to establish an RRC connection, for example, when the userattempts to call or when uplink data transmission is needed, or whentransmitting a message responsive to reception of a paging message fromthe EUTRAN.

In order for the idle UE 10 to be RRC connected with eNodeB 20, UE 10needs to perform the RRC connection procedure as described above. TheRRC connection procedure generally comes with the process in which UE 10transmits an RRC connection request message to eNodeB 20, the process inwhich eNodeB 20 transmits an RRC connection setup message to UE 10, andthe process in which UE 10 transmits an RRC connection setup completemessage to eNodeB 20. The processes are described in further detail withreference to FIG. 6.

1) The idle UE 10, when attempting to establish an RRC connection, e.g.,for attempting to call or transmit data or responding to paging fromeNodeB 20, sends an RRC connection request message to eNodeB 20.

2) When receiving the RRC connection message from UE 10, eNodeB 20accepts the RRC connection request from UE 10 if there are enough radioresources, and eNodeB 20 sends a response message, RRC connection setupmessage, to UE 10.

3) When receiving the RRC connection setup message, UE 10 transmits anRRC connection setup complete message to eNodeB 20. If UE 10successfully transmits the RRC connection setup message, UE 10 happensto establish an RRC connection with eNodeB 20 and switches to the RRCconnected state.

Meanwhile, when the UE 10 requests the RRC connection for the purpose ofdata transmission of the user plane, if the network, for example, thebase station (that is, eNodeB) is in the congest state, the UE 10 mayreject the request for the RRC connection.

In the overload and congest situation of the network, a method fordifferentiating the service per specific application of the UE isrequired. However, in the related art, there is no method ofimplementing the method.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to present a methodthat can solve the aforementioned problem.

In order to achieve the aforementioned purpose, one disclosure of thepresent specification provides a method for barring a network access.The method may be performed by a user equipment (UE) and comprise:receiving an application specific congestion control for datacommunication (ACDC) barring information and an access class barring(ACB) barring information; determining a category of an applicationbeing executed, according to a network access caused by the executedapplication; and performing a ACDC barring check based on the determinedcategory and the received ACDC barring information. Here, if the networkaccess caused by the executed application is not barred according to theACDC barring check, an ACB barring check to be performed based on theACB barring information is skipped.

The ACB barring check may be skipped based on an ACB barring checkskipping indication. Or, if the ACDC barring check is performed, the ACBbarring check may be skipped regardless of an ACB barring check skippingindication

The method may further comprise: although a barring timer is runningsince a previous network access has been barred according to a previousACB barring check, if a network access by the executed application isnot barred according to the ACDC barring check, stopping the barringtimer.

Although a previous network access has been barred according a previousACB barring check, if the network access is caused by the executedapplication, the category of the executed application may be determinedbased on an indication indicating that the barred network access resultsfrom the ACB barring check.

The category of the executed application may be determined based oninformation related to an attribute of the application.

The information related to an attribute of the application may includeat least one of: a group, a category, a priority, information and anidentifier of an application.

The ACDC barring information may include: a barring rate, a barringfactor, a barring time, a roaming information, and an access classbarring (ACB) skipping configuration, which are defined per a specificunit of an application.

In order to achieve the aforementioned purpose, one disclosure of thepresent specification provides a user equipment (UE) for barring anetwork access. The UE may comprise: a transceiver; a processorconfigured to control the transceiver and configured to perform:receiving an application specific congestion control for datacommunication (ACDC) barring information and an access class barring(ACB) barring information; determining a category of an applicationbeing executed, according to a network access caused by the executedapplication; and performing a ACDC barring check based on the determinedcategory and the received ACDC barring information. Here, if the networkaccess caused by the executed application is not barred according to theACDC barring check, an ACB barring check to be performed based on theACB barring information may be skipped.

According to a disclosure of the present specification, theaforementioned conventional technical problems can be solved. Morespecifically, an unnecessary service delay between a terminal and anetwork can be avoided in an application-based service environment of asystem. Further, an unnecessary waste of network resources can beprevented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural diagram of an evolved mobile communicationnetwork.

FIG. 2 is an exemplary diagram illustrating architectures of a generalE-UTRAN and a general EPC.

FIG. 3 is an exemplary diagram illustrating a structure of a radiointerface protocol on a control plane between UE and eNodeB.

FIG. 4 is another exemplary diagram illustrating a structure of a radiointerface protocol on a user plane between the UE and a base station.

FIG. 5a is a flowchart illustrating a random access process in 3GPP LTE.

FIG. 5b illustrates a connection process in a radio resource control(RRC) layer.

FIG. 6 illustrates a network overloaded state.

FIG. 7 is an exemplary flowchart illustrating an access barringoperation in a network congested state.

FIG. 8 illustrates an example in which an access due to all applicationsis barred, when ACB is applied.

FIG. 9 illustrates a signal flow showing a procedure based on ACDC.

FIG. 10 illustrates an exemplary signal flow showing ineffectiveness ofACDC.

FIG. 11 illustrates a signal flow showing a technical ambiguity whenACDC barring information, ACB barring information, and SSAC barringinformation are all provided.

FIG. 12 illustrates an exemplary signal flow of an ACDC procedureaccording to a proposal 1 of a first disclosure of the presentspecification.

FIG. 13 illustrates an exemplary processing method when ACDC barringinformation and ACB barring information are both provided.

FIG. 14 illustrates another exemplary processing method when ACDCbarring information and ACB barring information are both provided.

FIG. 15 illustrates another exemplary processing method when ACDCbarring information and ACB barring information are both provided.

FIG. 16 illustrates another exemplary processing method when ACDCbarring information and ACB barring information are both provided.

FIG. 17 and FIG. 18 illustrate an exemplary procedure according to aproposal 3 of the present specification.

FIG. 19 and FIG. 20 illustrate an exemplary procedure according to aproposal 4 of the present specification.

FIG. 21 is a configuration block diagram of UE 100 and a base station200 according to the exemplary embodiment of the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present invention is described in light of UMTS (Universal MobileTelecommunication System) and EPC (Evolved Packet Core), but not limitedto such communication systems, and may be rather applicable to allcommunication systems and methods to which the technical spirit of thepresent invention may apply.

The technical terms used herein are used to merely describe specificembodiments and should not be construed as limiting the presentinvention. Further, the technical terms used herein should be, unlessdefined otherwise, interpreted as having meanings generally understoodby those skilled in the art but not too broadly or too narrowly.Further, the technical terms used herein, which are determined not toexactly represent the spirit of the invention, should be replaced by orunderstood by such technical terms as being able to be exactlyunderstood by those skilled in the art. Further, the general terms usedherein should be interpreted in the context as defined in thedictionary, but not in an excessively narrowed manner.

The expression of the singular number in the specification includes themeaning of the plural number unless the meaning of the singular numberis definitely different from that of the plural number in the context.In the following description, the term ‘include’ or ‘have’ may representthe existence of a feature, a number, a step, an operation, a component,a part or the combination thereof described in the specification, andmay not exclude the existence or addition of another feature, anothernumber, another step, another operation, another component, another partor the combination thereof.

The terms ‘first’ and ‘second’ are used for the purpose of explanationabout various components, and the components are not limited to theterms ‘first’ and ‘second’. The terms ‘first’ and ‘second’ are only usedto distinguish one component from another component. For example, afirst component may be named as a second component without deviatingfrom the scope of the present invention.

It will be understood that when an element or layer is referred to asbeing “connected to” or “coupled to” another element or layer, it can bedirectly connected or coupled to the other element or layer orintervening elements or layers may be present. In contrast, when anelement is referred to as being “directly connected to” or “directlycoupled to” another element or layer, there are no intervening elementsor layers present.

Hereinafter, exemplary embodiments of the present invention will bedescribed in greater detail with reference to the accompanying drawings.In describing the present invention, for ease of understanding, the samereference numerals are used to denote the same components throughout thedrawings, and repetitive description on the same components will beomitted. Detailed description on well-known arts which are determined tomake the gist of the invention unclear will be omitted. The accompanyingdrawings are provided to merely make the spirit of the invention readilyunderstood, but not should be intended to be limiting of the invention.It should be understood that the spirit of the invention may be expandedto its modifications, replacements or equivalents in addition to what isshown in the drawings.

In the drawings, user equipments (UEs) are shown for example. The UE mayalso be denoted a terminal or mobile equipment (ME). The UE may be alaptop computer, a mobile phone, a PDA, a smartphone, a multimediadevice, or other portable device, or may be a stationary device such asa PC or a car mounted device.

Definition of Terms

For a better understanding, the terms used herein are briefly definedbefore going to the detailed description of the invention with referenceto the accompanying drawings.

An UMTS is an abbreviation of a Universal Mobile TelecommunicationSystem, and it refers to the core network of the 3rd generation mobilecommunication.

UE/MS is an abbreviation of User Equipment/Mobile Station, and it refersto a terminal device.

An EPS is an abbreviation of an Evolved Packet System, and it refers toa core network supporting a Long Term Evolution (LTE) network and to anetwork evolved from an UMTS.

A PDN is an abbreviation of a Public Data Network, and it refers to anindependent network where a service for providing service is placed.

A PDN connection refers to a connection from UE to a PDN, that is, anassociation (or connection) between UE represented by an IP address anda PDN represented by an APN.

A PDN-GW is an abbreviation of a Packet Data Network Gateway, and itrefers to a network node of an EPS network which performs functions,such as the allocation of a UE IP address, packet screening & filtering,and the collection of charging data.

A Serving gateway (Serving GW) is a network node of an EPS network whichperforms functions, such as mobility anchor, packet routing, idle modepacket buffering, and triggering an MME to page UE.

A Policy and Charging Rule Function (PCRF): The node of an EPS networkwhich performs a policy decision for dynamically applying QoS and abilling policy that are different for each service flow.

An Access Point Name (APN) is the name of an access point that ismanaged in a network and provides to UE. That is, an APN is a characterstring that denotes or identifies a PDN. Requested service or a network(PDN) is accessed via P-GW. An APN is a name (a character string, e.g.,‘internet.mnc012.mcc345.gprs’) previously defined within a network sothat the P-GW can be searched for.

A Tunnel Endpoint Identifier (TEID): The end point ID of a tunnel setbetween nodes within a network, and it is set for each bearer unit ofeach UE.

A NodeB is an eNodeB of a UMTS network and installed outdoors. The cellcoverage of the NodeB corresponds to a macro cell.

An eNodeB is an eNodeB of an Evolved Packet System (EPS) and isinstalled outdoors. The cell coverage of the eNodeB corresponds to amacro cell.

An (e)NodeB is a term that denotes a NodeB and an eNodeB.

An MME is an abbreviation of a Mobility Management Entity, and itfunctions to control each entity within an EPS in order to provide asession and mobility for UE.

A session is a passage for data transmission, and a unit thereof may bea PDN, a bearer, or an IP flow unit. The units may be classified into aunit of the entire target network (i.e., an APN or PDN unit) as definedin 3GPP, a unit (i.e., a bearer unit) classified based on QoS within theentire target network, and a destination IP address unit.

A PDN connection is a connection from UE to a PDN, that is, anassociation (or connection) between UE represented by an IP address anda PDN represented by an APN. It means a connection between entities(i.e., UE-PDN GW) within a core network so that a session can be formed.

UE context is information about the situation of UE which is used tomanage the UE in a network, that is, situation information including anUE ID, mobility (e.g., a current location), and the attributes of asession (e.g., QoS and priority)

OMA DM (Open Mobile Alliance Device Management): a protocol designed formanaging mobile devices such as mobile phones, PDAs, or portablecomputers and performs functions such as device configuration, firmwareupgrade, and error reporting.

OAM (Operation Administration and Maintenance): denotes a group ofnetwork management functions displaying network faults and providingcapability information, diagnosis and data.

NAS configuration MO (Management Object): MO (Management Object) used toconfigure in UE parameter associated with NAS functionality

NAS (Non-Access-Stratum): A higher stratum of a control plane between aUE and an MME. The NAS supports mobility management, session management,IP address management, etc., between the UE and the network.

MM (Mobility Management) operation/procedure: An operation or procedurefor mobility regulation/management/control of the UE. The MMoperation/procedure may be interpreted as including one or more of an MMoperation/procedure in a CS network, a GMM operation/procedure in a GPRSnetwork, and an EMM operation/procedure in an EPS network. The UE andthe network node (e.g., MME, SGSN, and MSC) exchange an MM message toperform the MM operation/procedure.

SM (Session Management) operation/procedure: An operation or procedurefor regulating/managing/processing/handling a user plane and/or a bearercontext/PDP context of the UE. The SM operation/procedure may beinterpreted as including one or more of an SM operation/procedure in aGPRS network and an ESM operation/procedure in an EPS network. The UEand the network node (e.g., MME and SGSN) exchange an SM message toperform the SM operation/procedure.

Low priority UE: A UE configured for NAS signalling low priority. Thestandard document 3GPP TS 24.301 and TS 24.008 may be incorporated byreference for details thereof.

Normal priority UE: A normal UE not configured with low priority.

Dual priority UE: A UE configured for dual priority. That is, a UE whichprovides dual priority support is configured for a NAS signalling lowpriority and also configured to override the NAS signalling low priorityindicator. The standard document 3GPP TS 24.301 and TS 24.008 may beincorporated by reference for details thereof.

PLMN: as an abbreviation of Public Land Mobile Network, means a networkidentification number of a mobile communication provider. In roamingcase of the UE, the PLMN is classifed into a home PLMN (HPLMN) and avistied PLMN (VPLMN).

Hereinafter, an aspect of the present specification is described withreference to the accompanying drawings.

FIG. 6 shows a network overload state.

As shown in FIG. 6, many UEs 100 a, 100 b, 300 c, and 300 d are presentin the coverage of an eNodeB 200, and data transmission/reception isattempted. Accordingly, if traffic is overloaded or congested in aninterface between the eNodeB 200 and an S-GW 520, downlink data to theMTC device 100 or uplink data from the UE 100 is not correctlytransmitted and thus data transmission fails.

Alternatively, even if an interface between the S-GW 520 and a PDN-GW530 or an interface between the PDN-GW 530 and an Internet Protocol (IP)service network of a mobile communication operator is overloaded orcongested, downlink data to the UEs 100 a, 100 b, 300 c, and 300 d oruplink data from the UEs 100 a, 100 b, 300 c, and 300 d is not correctlytransmitted and thus data transmission fails.

If an interface between the eNodeB 200 and the S-GW 520 is overloaded orcongested or if an interface between the S-GW 520 and the PDN-GW 530 isoverloaded or congested, a node (e.g., MME) of the core network performsa NAS level congest control to avoid or control signaling congestion andAPN congestion.

The NAS level congestion control consists of an APN based congestioncontrol and a general NAS level mobility management control.

The APN based congestion control implies an EMM, GMM, and (E)SM signalcongestion control related to a UE and a specific APN (i.e., an APNrelated to a congestion state), and includes an APN based sessionmanagement congestion control and an APN based mobility managementcongestion control.

On the other hand, the general NAS level mobility management controlimplies that a node (MME, SGSN) in the core network rejects a mobilitymanagement signaling request which is requested by the UE/MS in ageneral network congestion or overload situation to avoid the congestionand the overload.

In general, if the core network performs the NAS level congestioncontrol, a back-off timer value is transmitted to a UE in an idle modeor a connected mode by being carried on a NAS reject message. In thiscase, the UE does not request an EMM/GMM/(E)SM signal to the networkuntil the back-off timer expires. The NAS reject message is one of anAttach reject, a Tracking Area Updating (TAU) reject, a Routing AreaUpdating (RAU) reject, a service reject, an extended service reject, aPDN connectivity reject, a bearer resource allocation reject, a bearerresource modification reject, and a deactivate EPS bearer contextrequest reject.

The back-off timer may be classified into a Mobility Management (MM)back-off timer and a Session Management (SM) back-off timer.

The MM back-off timer operates independently for each UE, and the SMback-off timer operates independently for each APN and each UE.

Simply, the MM back-off timer is for controlling an EMM/GMM signal(e.g., Attach, TAU/RAU request, etc.). The SM back-off timer is forcontrolling an (E)SM signal (e.g., PDN connectivity, Bearer ResourceAllocation, Bearer Modification, PDP Context Activation, PDP ContextModification request, etc.).

More specifically, the MM back-off timer is a mobility managementrelated back-off timer used to control a case where a network congestionoccurs, and is a timer which prevents the UE from performing an attach,location information update (TAU, RAU), and service request procedureduring the timer is running. However, exceptionally in case of anemergency bearer service and a Multimedia Priority Service (MPS), the UEmay be allowed to perform the request even if the timer is running.

As described above, the UE may receive the MM back-off timer value froma core network node (e.g., MME, SGSN, etc.) or from a lower layer(access stratum). In addition, the timer value may be randomly set bythe UE within the range of 15 minutes to 30 minutes.

The SM back-off timer is a session management related back-off timerused to control a case where a network congestion occurs, and is a timerwhich prevents the UE from configuring or changing an associatedAPN-based session. However, likewise, exceptionally in case of anemergency bearer service and a Multimedia Priority Service (MPS), the UE100 may be allowed to perform the request even if the timer is running.

The UE receives the SM back-off timer value from the core network node(e.g., MME, SGSN, etc.), and is randomly set within up to 72 hours. Inaddition, the timer value may be randomly set by the UE/MS within therange of 15 minutes to 30 minutes.

On the other hand, when the congestion occurs in the eNodeB 200, theeNodeB 200 may perform congestion control. That is, when the UE requestsRRC connection establishment for data transmission of the user plane, ifthe eNodeB 200 is in the congest state, the eNodeB 200 may transmit areject response to the UE together with an extended wait timer. In thiscase, the RRC connection establishment request may not be re-attempteduntil the extended wait timer expires. On the contrary, when the UErequests the RRC connection for transmitting the signal of the controlplane for circuit switch (CS)-based call reception, even through theeNodeB 200 is in the congest state, the RRC connection request may notbe rejected.

FIG. 7 is an exemplary flowchart illustrating an access barringoperation in a network congested state.

As illustrated in FIG. 7, in the overload or congest state of thenetwork or the eNodeB 200, the eNodeB 200 may broadcast access classbarring (ACB)-related information through system information. The systeminformation may be system information block (SIB) type 2.

The SIB type 2 may include ACB-related information like the followingtable.

TABLE 2 Field Description ac-BarringFactor When a random value generatedby the UE is smaller than a value of ac-BarringFactor, access isallowed. If not, the access is barred. ac-BarringForCSFB ACB for circuitswitch (CS) fallback. The CS fallback converts a VoLTE call to aprevious 3G call. ac-BarringForEmergency ACB for emergency serviceac-BarringForMO-Data ACB for mobile orienting data ac-BarringForMO- ACBfor mobile orienting control signal Signalling ac-BarringForSpecialACACB for specific access classes, that is, 11 to 15. ac-BarringTimeRepresents time when the access is barred. ssac-BarringForMMTEL- ACB foreach service for mobile orienting of MMTEL video. Videossac-BarringForMMTEL- ACB for each service for mobile orienting of MMTELvoice. Voice

Meanwhile, UE1 100 a determines an IMS service, for example, mobileorienting of a call by VoLTE and generates a service request message.Similarly, UE2 100 b determines mobile orienting of general data andgenerate the service request message.

Sequentially, the UE1 100 a generates an RRC connection request message.Similarly, the UE2 100 b generate the RRC connection request message.

Meanwhile, the UE1 100 a performs access barring check (that is, whetherthe ACB is applied). Similarly, the UE2 100 b performs access barringcheck (that is, whether the ACB is applied).

If the ACB is not applied, the UE1 100 a and the UE2 100 b may transmita service request (alternatively, an extended service request) messageand the RRC connection request message, respectively. However, when theACB is applied, both the UE1 100 a and the UE2 100 b may not transmitthe RRC connection request message, respectively.

The access barring check will be described in detail as follows.Generally, at least one of 10 access classes (for example, AC0, AC1, . .. , and AC9) is randomly allocated to the UE. Exceptionally, for urgentemergency access, AC10 is allocated. As such, the value of the randomlyallocated access class may be stored in each USIM of the UE1 100 a andthe UE2 100 b. Then, the UE1 100 a and the UE2 100 b verify whether theaccess barring is applied, by using a barring factor included in thereceived ACB-related information, based on the stored access class. Theaccess barring check is performed in each access stratum (AS) layer,that is, an RRC layer of the UE1 100 a and the UE2 100 b.

The access barring check will be described in more detail as follows.

The ac-BarringPerPLMN-List is included in the SIB type 2 received byeach of the UE1 100 a and the UE2 100 b, and in the case whereAC-BarringPerPLMN entry matched with plmn-identityIndex corresponding tothe PLMN selected in an higher layer is included in theac-BarringPerPLMN-List, AC-BarringPerPLMN entry matched with theplmn-identityIndex corresponding to the PLMN selected by the higherlayer is selected.

Next, when the UE1 100 a and the UE2 100 b perform the RRC connectionrequest, the access barring check is performed by using T303 as Marringand using ac-BarringForMO-Data as a barring parameter.

When the barring is determined, each AS(RRC) layer of the UE1 100 a andthe UE2 100 b notifies a failure of the RRC connection establishment tothe higher layer.

Subsequently, as such, when the access is barred, each AS(RRC) layerdetermines whether a T302 timer or a Tbarring timer is driving. If thetimer is not driving, the T302 timer or the Marring timer is driven.

Meanwhile, while the T302 timer or a Tbarring timer is driving, theAS(RRC) layer considers that all the access to the corresponding cell isbarred.

As described above, in the network overload and congest situation, theeNB/RNC provides the ACB-related information to the UE. Then, the UEchecks the access barring by using the barring factor included in thereceived ACB information based on its access class stored in the USIM.Through the access barring check, finally, an access attempt is notperformed. That is, when the access to the corresponding cell is barredthrough the access barring check, the UE does not attempt the access,and when the access to the corresponding cell is not barred, the UEattempts the access. The access barring check is performed in the ASlayer. Herein, the access attempt means that the AS(RRC) layer of the UEtransmits the RRC connection request message to the eNB/RNC.

Meanwhile, the access barring check performs general mobile originating(MO) services of the UE, for example, originating call, originatingdata, originating IMS voice, and originating IMS video. That is, the ACBis applied to access of all application programs (but, except for aresponse to an emergency service or paging).

FIG. 8 illustrates an example in which access due to all applications isbarred, when ACB is applied.

As illustrated in FIG. 8, when it is determined that the ACB is applied,the access due to all of the applications of the UE (but, except for theresponse to an emergency service or paging) is fully barred.

As such, the access due to all of the applications is barred and thus,the differentiated service is impossible. The problem deterioratesnetwork resource waste and user's experience.

Accordingly, in the network overload and congest situation, a method fordifferentiating an MO service for each specific applicationgroup/category (for example, originating call or originating data) isrequired. However, in the related art, there is no method ofimplementing the method.

<Introduction of Application Specific Congestion Control for DataCommunication (ACDC)>

As a method of differentiating a normal mobile originating (MO) service,for example, originating call, originating data, originating IMS voice,and originating IMS video, it is proposed application specificcongestion control for data communication (ACDC).

FIG. 9 illustrates a signal flow showing a procedure based on ACDC.

This is described below with reference to FIG. 9.

First, a network (e.g., eNodeB) may provide ACDC barring information toa UE through SIB.

Meanwhile, when a specific application is executed in a UE 100 and adata communication service is required by the specific application, anapplication layer for controlling execution of the specific applicationprovides application attribute related information to an NAS layer.

Then, on the basis of the application attribute related informationreceived from the application layer, the NAS layer of the UE 100determines an application category for the ACDC.

Subsequently, when starting a service request procedure for a serviceconnection (transmission of a service request message or transmission ofan extended service request message), the NAS layer of the UE 100delivers information regarding the application category to an AS layer(i.e., RRC layer).

Before performing the service request procedure of the NAS layer(transmission of the service request message or transmission of anextended service request message), on the basis of the applicationcategory and ACDC barring information received from the network, the ASlayer (e.g., RRC layer) of the UE 100 performs ACDC barring check andthus determines whether to allow or not allow the service requestprocedure.

If it is determined not to be barred but to be allowed as a result ofthe ACDC barring check, the AS layer (i.e., RRC layer) of the UE 100transmits an RRC connection request message to an eNodeB 200.

As described above, a service request required by an applicationcurrently being executed in the UE through the ACDC may be allowed orbarred through differentiation.

However, once the service request is barred by the ACDC, any otherapplications in the UE cannot transmit the service request until a timerexpires. Therefore, even if the service request is transmitted by anapplication having a higher priority than an application which causesthe barring of the service request, ineffectively, the service requestis not accepted. This is described hereinafter with reference to FIG.10.

FIG. 10 illustrates an exemplary signal flow showing ineffectiveness ofACDC.

An AS layer (i.e., RRC layer) of a UE 100 performs ACDC barring checkand thus bars a request made by a first application. Subsequently, theAS layer drives a barring timer.

If it is barred as a result of the ACDC barring check as describedabove, the AS layer delivers an indication indicating that an access toa cell is barred to an NAS layer. Then, the NAS layer stops acorresponding NAS service request procedure.

Meanwhile, a second application having a higher priority requests aservice.

However, until an indication indicating alleviation of the barred accessto the cell is delivered to the NAS layer at the expiry of the barringtimer which is running in the AS layer (i.e., RRC layer), the NAS layercannot perform any differentiation as to the second application having ahigher priority than the first application which causes the barring.

Therefore, a service request made by the second application having ahigher priority than the first application which causes the barringeventually fails.

Once it is barred by the ACDC as described above, even if the servicerequest is made by the second application having a higher priority thanthe first application which causes the barring, ineffectively, theservice request is not accepted.

FIG. 11 illustrates a signal flow showing a technical ambiguity whenACDC barring information, ACB barring information, and SSAC barringinformation are all provided.

As can be seen from FIG. 11, a network (e.g., eNodeB) provides ACDCbarring information, ACB barring information, and service specificaccess control (S SAC) barring information to a UE 100.

In this case, it is not clear for the UE how to process several types ofbarring information.

Disclosure of the Present Specification

Accordingly, a disclosure of the present specification provides a methodof improving the aforementioned ineffectiveness and ambiguity.

Application attribute related information used in the presentspecification implies information including one of an applicationgroup/category/priority information/ID or one or more combinationsthereof. The application attribute related information may be reportedby a network to a UE through an attach procedure/TAU procedure/RAUprocedure. That is, the application attribute related information may beprovided/reported by the network to the UE through an attach acceptmessage, a TAU accept message, an RAU accept message. Alternatively, theapplication attribute related information may be provided to the UEthrough an NAS configuration management object (MO) or a new applicationmanagement object (MO) (e.g., access control MO for each application).Alternatively, the application attribute related information may bepre-configured in the UE by using USIM or the like.

In addition, application category information for ACDC impliesapplication group/category/priority mapping information determined onthe basis of the application attribute related information. Theapplication category information for the ACDC may be provided/reportedto a UE 100 through an attach/TAU/RAU procedure (e.g., attach acceptmessage, TAU accept message, RAU accept message). In this case, the UEmay provide capability indication/information for performing ACDCbarring check to the network through an attach/TAU/RAU procedure (e.g.,attach request message, TAU request message, RAU request message), andthereafter on the basis thereof (e.g., in case of supporting the ACDCbarring check), the application category information for the ACDC may beprovided/reported by the network to the UE 100 through theattach/TAU/RAU procedure (e.g., attach request message, TAU requestmessage, RAU request message). Further, the application categoryinformation for the ACDC may be included in an NAS configurationmanagement object (MO) or a new application MO (e.g., applicationspecific (access control) management object), and may be provided to theUE 100 through OMA DM. Otherwise, the application category informationfor the ACDC may be pre-configured in the UE 100 by using USIM or thelike.

In addition, ACDC barring information implies information including abarring ratio, barring factor, barring time, roaming information, andACB skip configuration defined for each application category for(specific) ACDC (i.e., information such as an applicationgroup/category/priority (group/category/priority) information/barringratio for each ID/barring factor, average barring time, ACB skipconfiguration (ACB skipping is On/configured/True or ACB skipping isOff/not configured/False), etc.).

I. First Disclosure of the Present Specification (Proposal 5 ofProvisional Application)

I-1. Proposal 1 of First Disclosure

The proposal 1 of the present specification relates to a method inwhich, when it is barred by a low application category as a result ofACDC barring check, an application category having a higher priorityoverrides the barring.

FIG. 12 illustrates an exemplary signal flow of an ACDC procedureaccording to the proposal 1 of the first disclosure of the presentspecification.

Referring to FIG. 12, a network (e.g., eNodeB) may provide ACDC barringinformation to a UE 100 through SIB. The ACDC barring information isdefined for each application category. It is shown in FIG. 11 that theACDC barring information is received by an AS layer (i.e., RRC layer) ofthe UE 100. However, the ACDC barring information may also be receivedby an application layer (or NAS layer). Alternatively, when a datacommunication service starts, the application layer may receive theinformation by requesting to the AS layer (i.e., RRC layer).

Meanwhile, when the application layer starts a data communicationservice, in order to differentiate a service of a specific application,the application layer provides the application attribute relatedinformation to the NAS layer, and the NAS layer determines theapplication category (or a plurality of application categories) for theACDC on the basis of the application attribute related information. Theapplication category information for the ACDC may be included in an NASconfiguration management object (MO) or a new application MO (e.g.,application specific (access control) management object), and may beprovided to the UE 100 through OMA DM. Otherwise, the applicationcategory information for the ACDC may be pre-configured in the UE 100 byusing USIM or the like.

Subsequently, the NAS layer provides the determined application categoryinformation (e.g., category C) to the AS layer (e.g., RRC layer).

In order to differentiate the application service, the AS layer performsACDC barring check by using the ACDC barring information received fromthe network, on the basis of the application category information (e.g.,category C) for the ACDC obtained from the NAS layer.

In this case, for example, if a category for an application for the ACDCis C, the AS layer performs the ACDC barring check on the basis of theapplication category C.

If an access to a serving cell is barred as a result of performing theACDC barring check, the AS layer (i.e., RRC layer) drives a barringtimer. The barring timer may be the same as a barring timer used in ACB,or may be a timer newly defined for the ACDC. Further, the AS layerdelivers an indication for reporting the barring to the NAS layer. Theindication for reporting the barring may be the same as an indicationused in case of being barred in the previous ACB check. Alternatively,the indication for reporting the barring may be a new indicationdifferent from the indication used in case of being barred in theprevious ACB check.

Then, the NAS layer stops a corresponding signaling connection requestprocedure (e.g., service request or extended service request procedure),a TAU/RAU request procedure, and an attach request procedure.

Further, the NAS layer records and manages a specific applicationcategory (e.g., category C) by which the service request procedure isbarred.

Meanwhile, the NAS layer of the UE 100 receives different applicationattribute related information from the application layer, and thusdetermines that the different application corresponds to an applicationcategory B for ACDC.

If the determined application category has a priority not higher than orequal to that of the application category which causes the barring, theNAS layer may not start an NAS signaling connection request procedurerequired by the application. However, if the determined applicationcategory B has a priority higher than that of the application category Cwhich causes the barring, the NAS layer starts an NAS signalingconnection request procedure required by an application belonging to theapplication category B.

The NAS layer delivers a service request message and informationregarding the determined application category to the AS layer.

Then, the AS layer stops the barring timer which is running. Further,the AS layer newly performs the ACDC barring check.

If the ACDC barring check is newly performed and a request of anapplication belonging to the application category having the higherpriority is barred, the AS layer provides an indication indicating thebarring to the NAS layer (or application layer), and drives the barringtimer. The running of the barring timer may be resuming from theprevious stopping, or may be running after initialization of the barringtimer.

However, if the request for the application belonging to the applicationcategory having the higher priority is allowed as a result of newlyperforming the ACDC barring check, the AS layer transmits an RRCconnection request message to an eNodeB.

I-2. Proposal 2 of First Disclosure

The proposal 2 proposes the aforementioned processing method of the UEwhen the network (e.g., eNodeB) provides all of ACDC barringinformation, SSAC barring information, and normal ACB barringinformation.

(i) As a first method, the UE may perform barring check (i.e., SSACbarring check and ACDC barring check) by using only SSAC relatedinformation and ACDC barring information. That is, the normal ACBbarring information is not used, and thus ACB barring check is notperformed. In this case, the network may additionally provide ACB skipinformation to the UE to indicate skipping of the normal ACB barringcheck. The ACB skip information may be received by an AS layer (i.e.,RRC layer) of the UE, and the AS layer (i.e., RRC layer) of the UE mayskip ACB check according to the received ACB skip information. In thiscase, the AS layer (i.e., RRC layer) of the UE may first perform SSACbarring check, and thereafter may perform the ACDC barring check.

(ii) As a second method, the UE may apply only the SSAC barringinformation and the normal ACB barring information. Accordingly, the UEdoes not perform the ACDC barring check. For example, if MMTELvoice/video or SMS over IP start indication can be provided (received)to an NAS layer of the UE in an IMS layer (or application layer), theNAS layer of the UE does not provide ACDC category information to the ASlayer (i.e., RRC layer). Accordingly, the AS layer (i.e., RRC layer) maynot perform the ACDC barring check. In this case, the UE first performsthe SSAC barring check, and then performs the normal ACB barring check.

(iii) As a third method, if the network provides all of SSAC barringinformation, ACB barring information, and ACDC barring relatedinformation, the UE performs barring check by applying several types ofbarring information in a predetermined order. For example, the UE firstperforms SSAC barring check, and then performs ACDC barring check andnormal ACB barring check. In this case, the UE may first perform theSSAC barring check, followed by the ACDC barring check and then(finally) the ACB barring check. Alternatively, the UE may first performthe SSAC barring check, followed by the ACB barring check and then(finally) the ACBC barring check.

(iv) As a fourth method, the UE may apply only normal ACB informationand ACDC barring related information. That is, the UE does not performthe SSAC barring check. In this case, the network may provide skipinformation to the UE to indicate skipping of the SSAC barring check.

This information may be received by the AS layer (i.e., RRC layer) andthen may be provided to an IMS or application layer. In this case, SSACmay not be performed in the IMS layer (or application layer), and ACDCbarring check proposed in the present invention and normal ACB may beapplied and performed. In this case, the ACDC barring check may be firstperformed, followed by the ACB, or the ACB may be first performed,followed by the ACBC barring check.

(v) As a fifth method, the UE may perform ACDC barring check by applyingonly ACDC barring related information. In this case, the network mayprovide skip information to the UE to indicate skipping of the SSACbarring check. The skip information may be received by the AS layer (orthe RRC layer) of the UE and thereafter may be delivered to the IMSlayer or the application layer. The IMS layer (or the application layer)may not perform the SSAC barring check on the basis of the skipinformation. Alternatively, when ACDC barring information received bythe AS layer (or the RRC layer) of the UE or an ACDCindication/information/parameter based thereon is delivered to the NASlayer, the NAS layer may deliver skip information/indication to the IMSlayer (or the application layer) to indicate skipping of the SSACbarring check. Accordingly, the IMS layer (or the application layer) maynot perform the SSAC barring check. Alternatively, in order to skip theSSAC barring check, the NAS layer of the UE may provide the AS layer(i.e., RRC layer) with information indication/information indicating notto provide the IMS layer (or application layer) with SSAC barringinformation received from the network (NAS→RRC: Not forwarding SSACbarring info to IMS).

According to this fifth method, only the ACDC barring check may beperformed.

The aforementioned fourth and fifth methods will be described in greaterdetail with reference to the drawings.

FIG. 13 illustrates an exemplary processing method when ACDC barringinformation and ACB barring information are both provided.

As can be seen from FIG. 13, when the ACDC barring information and theACB barring information are both provided to a UE 100, an AS layer ofthe UE 100 may first perform ACDC barring check, followed by ACB barringcheck.

FIG. 14 illustrates another exemplary processing method when ACDCbarring information and ACB barring information are both provided.

As can be seen from FIG. 14, when the ACDC barring information and theACB barring information are both provided to a UE 100, an AS layer ofthe UE 100 first performs ACDC barring check. In addition, according toa skip indication delivered from an NAS layer or irrespective of theskip indication, the AS layer of the UE 100 may skip or override the ACBbarring check.

On the other hand, when a network (e.g., eNodeB) provides ACDC barringrelated information and SSAC barring information and/or ACB skip relatedinformation for MMTEL voice/video or SMS over IP/SMS over NAS and/ornormal ACB barring information, the UE may skip ACB barring check forMMTEL voide/video or SMS over IP/SMS over NAS. In this case, the UEfirst performs SSAC barring check, and then skips ACB barring check asto the MMTEL voide/video or SMS over IP/SMS over NAS, and subsequentlyperforms ACDC barring check. Otherwise, even if the ACB skip relatedinformation for the MMTEL voice/video or SMS over IP/SMS over NAS isprovided from the network, the UE may perform only other access controlsinstead of skipping the ACB barring check. If the skip information andthe ACDC barring related information are used simultaneously, ACDCbarring check may be performed only for extra other service requestsinstead of performing the ACDC barring check for the MMTEL voice/videoor SMS over IP/SMS over NAS (that is, the ACDC barring check isskipped). In this case, the network (e.g., eNodeB) may provide an ACBskip indication for the MMTEL voide/video or SMS over IP/SMS over NAS tothe AS layer (i.e., RRC layer) through SIB2. The ACB skip indication mayimply skipping of only the ACB barring check or may imply skipping ofthe ACDC barring check as well. Alternatively, the network mayadditionally provide the ACB skip indication for skipping of the ACBbarring check and the ACDC skip indication for skipping of the ACDCbarring check.

Meanwhile, the NAS layer provides the AS layer (i.e., RRC layer) withthe determined category information when starting a service requestprocedure and a TAU/RAU/attach prequest procedure, and if it is barredas a result of performing the ACDC barring check, the AS layer (i.e.,RRC layer) provides the NAS layer with barring information/indicationindicating the barring. Then, the NAS layer records and manages aspecific application by which the barring is achieved. The barringinformation/indication indicating the barring as the result of ACDCcheck may be different from the barring information/indication based onthe result of ACB check. That is, the barring information/indicationindicating the barring as the result of ACDC check may be the same asthe barring information/indication based on the result of ACB check ormay be additional information/indication based on a result of additionalACDC check.

FIG. 15 illustrates another exemplary processing method when ACDCbarring information and ACB barring information are both provided.

Referring to FIG. 15, if it is barred as a result of performing ACBbarring check on the basis of ACB barring information received from anetwork, an AS layer (i.e., RRC layer) of a UE delivers barringinformation to an NAS layer to indicate the barring. Further, the ASlayer (i.e., RRC layer) of the UE drives a barring timer.

Meanwhile, the UE obtains ACDC barring information from the network. Ifa network access is requested by an application currently beingexecuted, an application layer of the UE provides application attributerelated information to the NAS layer.

Even if an access is barred, the NAS layer determines an applicationcategory (or a plurality of application categories) for ACDC on thebasis of the application attribute related information, and delivers thedetermined category to the AS layer. The AS layer performs ACDC barringcheck on the basis of the determined category. If it is not barred as aresult of performing the ACDC barring check, the AS layer (i.e., RRClayer) stops the barring timer and skips the ACB check.

As such, the ACDC may override barring based on the ACB.

Meanwhile, the barring indication may report only a fact that it isbarred. In this case, whether the barring is based on the ACB or isbased on the ACDC cannot be distinguished, and the same barringindication is used.

Meanwhile, in case of receiving a barring indication for which whetherthe barring is based on the ACB or the ACDC is not distinsuished, theNAS layer may distinguish which one is used in the barring according tothe following operation. First, when the NAS layer starts a servicerequest procedure (or extended service request procedure) or aTAU/RAU/attach request procedure, category information is provided tothe AS layer (i.e., RRC layer), and thereafter if the barring indicationis received from the AS layer (i.e., RRC layer), the NAS layer regardsthat the barring is based on the ACDC. However, if the categoryinformation is not provided to the AS layer (i.e., RRC layer) when theNAS layer starts the service request procedure (or extended servicerequest procedure) or the TAU/RAU/attach request procedure, the NASlayer regards that the barring is based on the ACB upon receiving thebarring indication from the AS layer.

On the other hand, separate barring indications may be used respectivelyfor a case wheter the barring is based on the ACB and a case where thebarring is based on the ACDC. This will be described below withreference to FIG. 16.

FIG. 16 illustrates another exemplary processing method when ACDCbarring information and ACB barring information are both provided.

Referring to FIG. 16, if a network access is requested by an applicationcurrently being executed, an application layer of a UE provides an NASlayer with application attribute related information.

The NAS layer does not determine a category for the applicationcurrently being executed, and thus delivers a service request message(or extended service request message) not including category informationand a TAU/RAU/attach request message to an AS layer.

If it is barred as a result of performing ACB barring check on the basisof ACB barring information received from the network, the AS layer(i.e., RRC layer) delivers a barring indication to the NAS layer toindicate that it is barred by ACB. Further, the AS layer (i.e., RRClayer) of the UE drives a barring timer.

Meanwhile, the UE obtains ACDC barring information from the network. Ifa network access is requested by an application currently beingexecuted, an application layer of the UE provides application attributerelated information to the NAS layer.

Even if an access is barred, the NAS layer determines an applicationcategory (or a plurality of application categories) for ACDC on thebasis of the application attribute related information, and delivers thedetermined category to the AS layer. The AS layer performs ACDC barringcheck on the basis of the determined category. If it is not barred as aresult of performing the ACDC barring check, the AS layer (i.e., RRClayer) stops the barring timer and skips the ACB check.

As such, the ACDC may override barring based on the ACB.

On the other hand, the NAS layer of the UE may check whether it is setto any one of access classes (ACs) 11 to 15, and only when it is not setto the ACs 11 to 15, ACDC barring check may be performed based on theACDC barring information. If it is set to the ACs 11 to 15, the NASlayer does not use the ACDC barring information. In this case, the NASlayer does not determine a category for the application currently beingexecuted, and thus does not provide category information to the AS layer(i.e., RRC layer). Then, since the category information is not providedto the NAS layer, the AS layer (i.e., RRC layer) does not apply the ACDCbarring information and thus performs only normal ACB barring checkwithout having to perform the ACDC barring check.

The content described up to now will be described again as followsaccording to the sections 5.3.3.2 of standard TS 36.331(v12.7.0)document.

If a higher layer of a UE requests to establish an RRC connection, theUE operates as follows.

1> If the higher layer indicates that the RRC connection corresponds toACDC,

2> and if an SIB type 2 includes ACDC-BarringPerPLMN-List and includesACDC-BarringPerPLMN having plmn-IdentityIndex corresponding to PLMNselected by the higher layer,

3> an ACDC-BarringPerPLMN entry having plmn-IdentityIndex correspondingto PLMN selected by the higher layer is selected.

3> Further, irrespective of a common barring parameter included in theSIB type 2, the selected ACDC-BarringPerPLMN entry is used for ACDCbarring check.

2> Otherwise,

2> the common barring parameter included in the SIB type 2 is used forACDC barring check.

2> If the SIB type 2 includes ac-BarringForACDC,

3> if the ac-BarringForACDC includes a BarringPerACDC-Category entrycorresponding to an ACDC category selected by the higher layer,

4> the BarringPerACDC-Category-r13 entry corresponding to the ACDCcategory selected by the higher layer is selected.

3> Otherwise,

4> a last BarringPerACDC-Category entry in BarringPerACDC-CategoryListis selected.

3> If it is intended to establish the RRC connection for originatingcall,

4> barring check is performed by using T3xx as Tbarring and by usingBarringPerACDC-Category-r13 as an AC barring parameter.

4> If an access for a cell is barred,

5> it is reported to the higher layer that the establishment of the RRCconnection has failed, and it is reported to the higher layer that anaccess for the originating call is barred by ACDC.

3> Otherwise, if the UE intends to establish the RRC connection fororiginating signaling,

4> barring check is performed by using T3yy as Tbarring and by usingBarringPerACDC-Category-r13 as an AC barring parameter.

4> If an access of a cell is barred,

5> it is reported to the higher layer that the establishment of the RRCconnection has failed, and it is reported to the higher layer that anaccess for the originating signaling is barred by ACDC.

The content described up to now will be described again as followsaccording to the sections 5.3.3.4 of standard TS 36.331(v12.7.0)document.

The UE performs the following operation.

1> A radio resource configuration procedure is performed according toreceived radioResourceConfigDedicated.

1> If it is stored, cell reselection priority information provided byidleModeMobilityControllnfo is deleted.

1> If a T3xx timer is running, the timer stops.

1> If a T3yy timer is running, the timer stops.

1> A procedure based on the section 5.3.3.5 is performed as follows.

The content described up to now will be described again as followsaccording to the sections 5.3.3.5 of standard TS 36.331(v12.7.0)document.

The UE performs the following operation.

1> During a T300, T302, T303, T305, T306, T3xx, or T3yy timer isrunning, if cell reselection occurs,

2> if a T302, T303, T305, T306, T3xx, and/or T3yy timer is running,

3> the running T302, T303, T305, T306, T3xx, T3yy timer stops.

3> A procedure based on the section 5.3.3.7 is performed as follows.

The content described up to now will be described again as followsaccording to the sections 5.3.3.7 of standard TS 36.331(v12.7.0)document.

1> If a T3xx timer expires or stops,

2> if a T302 timer is not running,

3> it is reported to the higher layer that ACDC barring for originatingcall is alleviated.

1> If a T3yy timer expires or stops,

2> if a T302 timer is not running,

3> it is reported to the higher layer that ACDC barring for originatingsignaling is alleviated.

The content described up to now will be described again as followsaccording to the sections 5.3.3.11 of standard TS 36.331(v12.7.0)document.

1> If a T302 timer or “Tbarring” is running and if the timer is notrelated to ACDC,

2> it is regarded that an access for a cell is barred.

1> Unlike the aforementioned description, if the SIB type 2 includes an“AC barring parameter”,

2> if the UE has any one of valid ACs 11 to 15 stored in USIM,

2> if a corresponding bit in ac-BarringForSpecialAC included in the ACbarring parameter is set to 0 as to at least one of the valid ACs,

3> it is regarded that an access to a cell is barred.

2> Otherwise,

3> a random value rand distributed uniformly is generated to satisfy arange of 0≤rand<1.

3> If the rand is less than a value indicated by acdc-BarringFactorincluded in ACDC barring parameter,

4> it is regarded that an access to a corresponding cell is not barred.

3> Otherwise,

4> it is regarded that the access to the corresponding cell is barred.

The content described up to now will be described again as followsaccording to the sections 6.3.1 of standard TS 36.331(v12.7.0) document.

An eNodeB transmits the SIB type 2 including common radio resourceconfiguration information to all UEs. The SIB type 2 may include thefollowing information.

TABLE 3 [[ ac-BarringForACDC-r13 BarringPerACDC-CategoryList- r13OPTIONAL, -- Need OP ]] } ACDC-BarringPerPLMN-List-r13 ::= SEQUENCE(SIZE (1.. maxPLMN-r11)) OF ACDC-BarringPerPLMN-r13ACDC-BarringPerPLMN-r13 ::= SEQUENCE { plmn-IdentityIndex-r13 INTEGER(1..maxPLMN-r11), ac-BarringForACDC BarringPerACDC-CategoryList- r13OPTIONAL, -- Need OP } BarringPerACDC-CategoryList-r13 ::= SEQUENCE(SIZE (1.. maxACDC-Cat-r13)) OF BarringPerACDC-Category-r13BarringPerACDC-Category-r13 ::= SEQUENCE { acdc-BarringConfig-r13SEQUENCE { ac-BarringFactor-r13 ENUMERATED { p00, p05, p10, p15, p20,p25, p30, p40, p50, p60, p70, p75, p80, p85, p90, p95},ac-BarringTime-r13 ENUMERATED {s4, s8, s16, s32, s64, s128, s256, s512}} OPTIONAL }

Each field of the above table is described below.

[Table 4]

SIB type 2 field description

acdc-BarringConfig-r13

If this parameter does not exist in a first entry ofbarringPerACDC-CategoryList as to a higher ACDC category, a value ofac-BarringFactor of this parameter is set to 1.

If this parameter does not exist in an entry ofbarringPerACDC-CategoryList as to an ACDC category, it is regarded asthe same as a previous entry of the barringPerACDC-CategoryList.

barringPerACDC-CategoryList-r13

It is a list of barringPerACDC-Category for each ACDC category. A firstentry in this list corresponds to a highest ACDC category. The highestcategory is a category which is barred to the minimum extent in anattempt of accessing a cell. A second entry in the list corresponds to asecond highest ACDC category. The second highest ACDC category has ahigher barring probability than the highest category. A last entry inthe list corresponds to a lowest ACDC category. The lowest ACDC categoryhas a highest barring probability.

Meanwhile, a timer is summarized as shown in the following table.

TABLE 5 Timer starting condition stopping condition at the expiry oftimer T3xx When performing When entering the RRC It is reported to thehigher RRC connection connected state and when layer that ACDC barringis establishment for performing cell alleviated. originating call, andreselection. when the access is barred by ACDC. T3yy When performingWhen entering the RRC It is reported to the higher RRC connectionconnected state and when layer that ACDC barring is establishment forperforming cell alleviated. originating signaling reselection. and whenthe access is barred by ACDC.

II. Second Disclosure of the Present Specification (Proposals 10 and 15of Provisional Applications)

When a UE is set to a low priority (i.e., the UE is set to NAS signalinglow priority) or a dual priority (i.e., the UE is not set to the NASsignaling low priority), this means that service differentiation (ACDCbarring check) is not performed according to the disclosure of thepresent specification.

Otherwise, when the UE is set to the low priority (i.e., the UE is setto the NAS signaling low priority) or the dual priority (i.e., the UE isnot set to the NAS signaling low priority), an access control may beperformed by applying SSAC, ACB, or the like instead of performing theACDC barring check according to the disclosure of the presentspecification.

When the UE is set to the low priority (i.e., the UE is set to the NASsignaling low priority) or the dual priority (i.e., the UE is not set tothe NAS signaling low priority), a low priority indicator in a deviceproperties IE of an NAS message (an EMM NAS message and an ESM message:attach request, TAU request, RAU request, service request, extendedservice request, PDN connectivity request, bear resource allocationrequest, bearer resource modification request, etc.) implies that the UEis set to the NAS signaling low priority or the UE is not set to the NASsignaling low priority.

Meanwhile, if the UE/MS set to the NAS signaling low priority andextended access barring (EAB) receives ACDC barring information for eachACDC category from a network (e.g., eNB/NB, MME/SGSN), the applicationlayer and the NAS and AS layer (i.e., RRC layer) perform serviceconnection differentiation (ACDC barring check) and do not perform theEAB. Alternatively, only the EAB may be performed and the serviceconnection differentiation (ACDC barring check) may not be performed.Alternatively, the service connection differentiation (ACDC barringcheck) and the EAB may be both performed. Whether to perform the serviceconnection differentiation and the EAB may be finally determinedaccording to a network configuration or a UE configuration.

III. Proposal 3 of the Present Specification (Proposal 13 of ProvisionalApplication)

Hereinafter, the proposal 3 of the present specification will bedescribed with reference to the drawings.

FIG. 17 and FIG. 18 illustrate an exemplary procedure according to theproposal 3 of the present specification.

(step0) First, although not shown, ACDC category information may bedefined/configured in NAS configuration management object (MO) or newapplication MO (e.g., application specific (access control) managementobject), and in this case, the ACDC category information of the NASconfiguration MO or the new application MO (e.g., the applicationspecific (access control) management object) may be provided to a UEthrough OMA DM. Otherwise, the ACDC category information may bepre-configured in the UE using USIM or the like. In this case, an NASlayer or application layer (or application control layer including anoperating system (OS)) or AS layer (i.e., RRC layer) of the UE mayobtain ACDC category related information through an AT-command or thelike.

(step1) A network (i.e., eNodeB) provides the ACDC barring relatedinformation to the UE through SIB. More specifically, the ACDC barringinformation may be provided when the UE is in an EMM-idle orEMM-connected mode (RRC-idle or RRC-connected mode). The ACDC barringrelated information is received by the AS layer (i.e., RRC layer) of theUE from the network. The AS layer (i.e., RRC layer) provides the NASlayer (or IMS layer or application layer) with the ACDC barring relatedinformation provided from the network. This information may be providedby the AS layer (i.e., RRC layer) periodically or when an eventoccurs/changes or when the NAS layer (or IMS layer or application layer)requests to provide the information.

If the ACDC barring related information and normal ACB barringinformation are simultaneously provided to the AS layer (i.e., RRClayer) from the network (i.e., eNodeB) through SIB, the AS layer (i.e.,RRC layer) of the UE may provide both of the ACDC barring relatedinformation and the ACB barring information to the NAS layer (or IMSlayer or application layer).

The application layer provides application attribute relatedinformation/ID to the NAS layer when a service connection is attemptedto provide an application service (e.g., originating data or originatingsignaling). Further, (service connection session) setting/startindication/information may be provided together to the NAS layer.

(step2) When an application service start request and the applicationattribute related information/ID are provided from the applicationlayer, the NAS layer performs a service request procedure (i.e., servicerequest or extended service request) or a TAU procedure (i.e.,transmission of a tracing area update request message). In this case, anACDC category for the application attribute related information/IDprovided from the application layer is determined on the basis of theACDC category information obtained in the above step 0. Thereafter, ACDCbarring check is performed on the basis of the ACDC barring informationprovided from the AS layer (i.e., RRC layer). Upon passing the ACDCbarring check, the service request procedure (i.e., service request orextended service request) or the TAU procedure is performed. Uponfailing to pass the ACDC barring check, the service request procedure orthe TAU procedure is not performed.

(step3) When a service request procedure or a TAU procedure starts foran application service connection of the NAS layer, if ACDC barringinformation provided from the network (i.e., eNodeB) and normal ACBbarring information are provided simultaneously, the AS layer (i.e., RRClayer) does not apply (or does override) the normal ACB barringinformation and performs an RRC connection establishment requestprocedure for the application service connection. In this case, since itpasses the ACDC barring check for the application service connection ofthe NAS layer, the AS layer (i.e., RRC layer) may recognize that theservice request procedure or the TAU procedure has started. Otherwise,if an indication/information for skipping/overriding the normal ACBbarring check is provided together from the NAS layer to the AS layer(i.e., RRC layer), the normal ACB barring check is skipped/overridden,and the RRC connection establishment procedure is performed for theapplication service connection.

IV. Proposal 4 of the Present Specification (Proposal 14 of ProvisionalApplication)

Hereinafter, the proposal 4 of the present specification will bedescribed with reference to the drawings.

FIG. 19 and FIG. 20 illustrate an exemplary procedure according to theproposal 4 of the present specification.

(step0) Identical to the proposal 3 of the present invention.

(step1) Identical to the proposal 3 of the present invention.

(step2) When an application service start request and an applicationattribute related information/ID are provided from an application layer,an NAS layer performs a service request procedure or a TAU procedure. Inthis case, the application attribute related information provided fromthe application layer is delivered/provided together to an AS layer(i.e., RRC layer).

Further, service connection session setting/start indication informationprovided from the application layer may be provided together to the NASlayer.

(step3) When a service request procedure or a TAU procedure starts foran application service connection of the NAS layer, the AS layer (i.e.,RRC layer) determines an ACDC category(s) regarding applicationattribute related information provided from the NAS layer on the basisof the ACDC category information obtained in the above step 0.Thereafter, an RRC connection request procedure is performed for theapplication service connection. In this case, if ACDC barringinformation provided from the network (i.e., eNodeB) and normal ACBbarring information are provided simultaneously, the normal ACB barringinformation is not applied but overridden, and ACDC barring check isperformed for the RRC connection establishment request procedure for theapplication service connection. In this case, the AS layer (i.e., RRClayer) performs the ACDC barring check by using only ACDC barringinformation for each ACDC category provided from the network (i.e.,eNodeB). Upon passing the ACDC barring check, the AS layer (i.e., RRClayer) performs the RRC connection establishment request procedure.Otherwise, if an indication for skipping/overriding the normal ACBbarring check is provided together to the AS layer (i.e., RRC layer)from the NAS layer, the ACB barring check is skipped/overridden and theACDC barring check is performed for the RRC connection establishmentprocedure for the application service connection.

Alternatively, if the ACDC barring information of the present inventionand the normal ACB barring information are provided simultaneously tothe UE from the network (i.e., eNodeB) through SIB, the UE may firstperform ACDC barring check in the NAS layer by applying only the ACDCbarring information, and upon passing the ACDC barring check, mayperform ACB barring check for applying the ACB barring information inthe AS layer (i.e., RRC layer). That is, the ACDC barring check and theACB barring check perform in an overlapping manner.

Otherwise, an access control may be performed by selectively applyingthe ACDC barring information and the normal ACB barring informationaccording to an indication/configuration from the network(MME/SGSN/eNB/NB, etc.) (Any one of the ACDC barring check and the ACBbarring check is performed).

Alternatively, if the AS layer additionally (or separately) receives anACB skip indication from the NAS layer, the application serviceconnection attempt is allowed by skipping the ACB barring checkirrespective of a current access barring state. That is, even if it isin an access barring state at present, the RRC connection establishmentprocedure is performed by ignoring the barring state.

Meanwhile, in the aforementioned content, ACB barring check based oninformation of a barring ratio for each applicationgroup/category/priority information, a barring factor, an averagebarring time, an ACB skip configuration, or the like may imply the ACDCbarring check.

Meanwhile, the proposals described above may be combined.

The contents described above may be implemented by hardware. This willbe described with reference to the accompanying drawings.

FIG. 21 is a configuration block diagram of UE 100 and a base station200 according to the exemplary embodiment of the present invention.

As illustrated in FIG. 21, the UE 100 includes a storage means 101, acontroller 102, and a transceiver 103. In addition, the base station 200includes a storage means 201, a controller 202, and a transceiver 203.

The storage means 101 and 201 store the aforementioned methods.

The controllers 102 and 202 control the storage means 101 and 201 andthe transceivers 103 and 203. In detail, the controllers 102 and 202execute the methods stored in the storage means 101 and 201,respectively. In addition, the controllers 102 and 202 transmit theaforementioned signals through the transceivers 103 and 203.

Although preferable embodiments of the present invention has beenexemplarily described as above, the scope of the present invention islimited to only the specific embodiments, and as a result, variousmodifications, changes, or enhancements of the present invention can bemade within the spirit of the present invention and the scope disclosedin the appended claims.

What is claimed is:
 1. A method for barring a network access, the methodperformed by a user equipment (UE) and comprising: determining anapplication specific congestion control for data communication (ACDC)category for a network access request; and performing an access barringcheck for the ACDC, based on the determined ACDC category, wherein theaccess barring check for the ACDC is used to determine whether thenetwork access request is to be barred or not, wherein the networkaccess request is not to be barred based on the access barring check forthe ACDC, even if a previous network access has been barred based on aprevious access barring check for an access class barring (ACB).
 2. Themethod of claim 1, further comprising: receiving ACDC barringinformation, wherein the access barring check for the ACDC is performedbased on the ACDC barring information.
 3. The method of claim 2, whereinthe ACDC barring information includes at least one of: a barring rate, abarring factor, a barring time, roaming information, or an access classbarring (ACB) skipping configuration, which are defined per a specificunit of an application.
 4. The method of claim 1, further comprising:receiving ACB barring information, wherein the previous access barringcheck for the ACB is performed based on the ACB barring information. 5.The method of claim 1, further comprising: stopping a barring timer ifthe network access request is not barred according to the access barringcheck for the ACDC.
 6. The method of claim 5, wherein the barring timeris run when the previous network access is barred according to theprevious access barring check for the ACB.
 7. The method of claim 1,further comprising: if the network access request is barred according tothe access barring check for the ACDC, indicating, by an Access Stratum(AS) layer to a Non-Access Stratum (NAS) layer, that the network accessrequest is barred.
 8. The method of claim 1, further comprising:indicating, by an Access Stratum (AS) layer to a Non-Access Stratum(NAS) layer, that the barred network access results from the previousaccess barring check for the ACB.
 9. A user equipment (UE) for barring anetwork access, the UE comprising: a transceiver; and a processorconfigured to control the transceiver and configured to: determine anapplication specific congestion control for data communication (ACDC)category for a network access request; and perform an access barringcheck for the ACDC, based on the determined ACDC category, wherein theaccess barring check for the ACDC is used to determine whether thenetwork access request is to be barred or not, wherein the networkaccess request is not to be barred based on the access barring check forthe ACDC, even if a previous network access has been barred based on aprevious access barring check for an access class barring (ACB).
 10. TheUE of claim 9, wherein the transceiver is configured to: receive ACDCbarring information, wherein the access barring check for the ACDC isperformed based on the ACDC barring information.
 11. The UE of claim 9,wherein the transceiver is configured to: receive ACB barringinformation, wherein the previous access barring check for the ACB isperformed based on the ACB barring information.
 12. The UE of claim 9,wherein the processor is further configured to: stop a barring timer ifthe network access request is not barred according to the access barringcheck for the ACDC.
 13. The UE of claim 12, wherein the barring timer isrun when the previous network access is barred according to the previousaccess barring check for the ACB.
 14. The UE of claim 9, wherein theprocessor is further configured to include an Access Stratum (AS) layerand a Non-Access Stratum (NAS) layer, wherein the AS layer indicates, tothe NAS layer, that the network access request is barred, if the networkaccess request is barred according to the access barring check for theACDC.
 15. The UE of claim 9, wherein the processor is further configuredto include an Access Stratum (AS) layer and a Non-Access Stratum (NAS)layer, wherein the AS layer indicates, to the NAS layer, that the barrednetwork access results from the previous access barring check for theACB.